1. Field of the Invention
The invention relates in general to an illumination systems, and more particularly to a dual lamp illumination system.
2. Description of the Related Art
Projection systems are widely used in various applications. In a conventional projection system, an arc lamp is used for generating an optical beam. The optical beam, through the color wheel, is then filtered into red, green and blue components. The filtered optical beam is in turn directed towards a light pipe, for modifying the distribution of the optical beam and making the light intensity distribution more uniform.
The optical beam from the light pipe is then relayed by relay optics, such as condensing lens and mirrors, to a digital micro-mirror device (DMD). The DMD includes a number of micro mirrors that can be arranged to either selectively reflect the optical beam towards projection lens to produce image light, or block the optical beam from getting through the projection lens. The optical beam from the projection lens is then projected onto the display screen, thereby displaying an image.
However, the arc lamps used by the conventional projection system often cannot be scaled up to high enough power levels. That is, low lumens level causes the image projected on display screen to appear dark. Due to such inherent drawbacks, methods for increasing power levels have thus been an important topic.